Does radio get past engine?

[alf jessup]

Thanks for the replies fellas.Most of the info given went straight over my head; I'm not stupid (stop it SD) but electronics and formulas make my eyes glaze over.

Scott -the aircraft is all wood with fabric skin (but remember the fabric is sprayed with a thin layer of aluminium to block UV). I use the remote mic on my DC headset and yes, there is a fair bit of cabin noise so I sometimes have to throttle back when transmitting.

 

Nobody -the antenna was supplied by SMC, along with a Black Widow TT2000 extension cable designed for aircraft radio band.

 

I was advised to install the dipole vertically, but it doesn't fit, so it's mounted at an angle. Having read the links sent, it seems I might be best off to mount it horizontally. It will fit in one wing leading edge (I can slip it in past the ribs) or inside the tailplane.

Old Koreelah,

 

Black Widow aerial kit ???, hmmmm, every trike mate of mine that spent quite a bit of money on them for the so called best you can get went back to the standard dipole as their reception & transmitting was crap with every one of them that bought one, back to a standard $25 dipole and reception was excellent again, never had 1 good report from a BW aerial.

 

Just my 20 bob's on your possible problem

 

Alf

 

 

[jetboy]

I'm not sure that you actually have a half-wave dipole in there. It would need to be around 48". There are some designs which are in the form of a folded unipole, or an end- fed vertical often referred to as a J-pole

 

Most times a standard quarter wave whip (24") with some form of groundplane - 3 or 4 metal tape strips glued inside and 20" long each would do.

 

looking at your lovely photo I can see another possibility. If your stall fences are ali and the upper rear end is not in contact with any metal, you may be able to connect your coax cable braid to either the mid point of the leading edge inner curve and the coax inner connection to the lower tip of the fence - on the inside radius. Or you may need to slide the braid further round the upper fence to get a match. Technically this would be called a low profile antenna or train antenna. If your fences are plywood its actually even easier you can glue a wire around the outside of the fence, cutting the dimensions to suit the frequency.

 

Sorry for the technical bits and you'd need some test gear to get these to work. A store bought quarter wave whip with groundplane strips works 98% of the time, and keeps the signal above & outside the fuselage both radiating and receiving wise. I worked on turbine aircraft where mounting antennas too close to the cockpit & engine caused trouble with instrumentation and headsets.

 

Ralph

 

 

[sain]

if you want to put together some radials to act as a ground plane for the antenna to work against you could try adhesive copper tape from bunnings or masters. Look in the garden section for barrier tape intended to stop slugs (apparantly they don't like to cross copper).

 

Its about $7 a roll, and its cheaper at Masters than Bunnings (Bunnings said they won't price match as they are different brands, despite all the dimensions being the same).